The permian period ended in the greatest extinction of the eon.

The correct answer will be Phanaerozoic eon.

Explanation:

The Permian period was the period which took place between 299 to 251 million years ago. This period was observed with the emergence of a supercontinent called Pangaea and extreme climate on this continent.

This period was ended with a mass extinction which is considered as one of the worst extinction events in the history of the planet which took place around 251 million years ago in the Phanerozoic eon. This extinction ended about 70 percent of land animals and 90 per cent of all marine species.

Thus, Phanerozoic eon is the correct answer.

multiply it by 5 in order for you to understand i cant give an exact answer.